Rearch On Seismic Response Analysis Method Of Arch Dam Considering The Effect Of Valley Site

Valley topography has a great influence on the seismic responses of the vallysite, but for the convenience of calculation, the lateral boundary of thethree-dimensional dam-foundation model is usually simplified as level layered halfspace for solving the free field (In this paper, be called the approximate solution offree field). The actual earthquake input of the arch dam-foundation system isdifferent to the approximate soulution obviously. Consequently, in the seismicresponse analysis of arch dam-foundation dynamic interaction, the accuracy andreliability of calculation results are decided by the reasonability of the earthquakewave input. And then in this paper Xiaowan arch dam is selected as a3D elementmodel, the following series work: the simulation method of irregular landform, theeffects of vally site on arch dam’s seismic response, and the input ground motion intime domain anlysis of arch dam-foundation system are performed in this paper. Themain results are as follows:Firstly, the free field’s calculation method of3D irregular site is put forward inthis paper. The finite element method and artificial transmitting boundary areadopted to solve the seismic response of two-dimensional irregular site(In this paper,be called the finite-element solution of free field), and take the calculating results asthe free field input of three-dimensional calculation model. Then, the seismicresponse simulation of3D Valley site of Xiaowan Arch Dam is performed. Thefinite-element and approximate free field’s solutions of the lateral boundary and theeffects of valley topography on internal site’s seismic response are compared andanalysed. The results show that: large differences occur between the finite-elementfree field’s solutions and the approximate free field’s solutions. The differentsolving methods of free field have obvious influence on the seismic responses of thevally site.Secondly, the seismic response analysis method of3D arch dam-foundationmodel is put forward under the condition of considering the effects of vally site. Thefinite-element and approximate solutions of free field are taken as the earthquakeinput of the3D model, then comparing the seismic response of3D archdam-foundation model under the condition of different earthquake input. The resultsshow that: Great differences occur between the finite-element method and theapproximate method. Although the displacement response of arch dam andfoundation have little changes, but the stress responses of arch dam increases greatlywhen adopting the finite-element solution of free field.Thirdly, the seismic response analysis method of3D arch dam-foundation modelunder the condition of inclined incident earthquake wave is put forward whenconsidering the the effects of vally site. The finite element method and artificial transmitting boundary are adopted to solve the free field of lateral boundary withvally topography under the condition of inclined incident earthquake wave. And thentake the calculating results as the free field input of three-dimensional calculationmodel, the seismic response of3D arch dam-foundation system under the conditionof inclined incident earthquake wave is resloved. The calculation results show that:The stress response of arch dam and foundation has great changes when theearthquake wave inclined incidence.Fourthly, the calculation method of free field with valley topography is putforward under the bidirectional earthquake wave input case when considering thedifferent vibration direction of incident earthquake wave. Then the seismic responseof arch dam and foundation is simulated considering the different vibration directionof bidirectional incident earthquake wave. The results show that: in the case ofunidirectional earthquake wave input, the maximum seismic response of arch damand foundation occur when the vibration direction of input earthquake wave is acrossor along the river. But in the case of bidirectional earthquake wave input, themaximum displacement and strain responses of arch dam occur when the vibrationdirection isn’t across or along the river, the maximum responses are related to theinput earthquake wave.Finally, the whole study work is summarized and the prospects on the futureprogress of the work are proposed.